Method of forging cylinder heads



y 15, 1947' c. A. BRAucHLER 7 2,424,075

METHOD OF FORGING CYLINDER HEADS Filed June 11, 1943 7 Sheets-Sheet l Cizaresfl.Bra/mhler my? a 2, 4 f

Jul 15, 1947.

C. A. BRAUCHLER METHOD OF FORGING CYLINDER HEADS Filed June 11, 1945 7 Sheets-Sheeb 2 July 15, 1947.

c. A. BRAUCHLER- METHOD OF FORGING CYLINDER HEADS 7 Sheets-Sheet 5 Filed June 11, 1943 July 15, 1947. Q BRAUCHLER 2,424,075

METHOD OF FORGING CYLINDER HEADS Filed June 11, 1943" 7 Sheets-Sheet 4 Swim/M (jmlasfl flraadzler July 15, 1947. c. A. BRAUCHt-ER 2,424,975

METHOD OF FORGING CYLINDER HEADS 7 Sheets-Sheet 5 Filed June 11, 1943 ND WH mm .QQ RI Q V aha/ 265 Afizwmzek' W izy ggz July 15, 194?. Q A, BRAUCHLER 2,424,075

I METHOD OF FORGING CYLINDER HEADS .Filed June 11, 1943 7 Sheets-Sheet 6 swam tow CWZesABrauc/der M'Q VM. fi a W c ER eeeeeeeeeeee t7 gvwe/wtom Patented July 15, 1947 UNITED STATES PATENT OFFICE 2,424,075 METHOD OF FORGING CYLINDER HEADS Charles A. Brauchlcr, Canton, Ohio Application June 11, 1943, Serial No. 490,407

13 Claims. 1

The invention relates to a novel method and apparatus for forging, and more particularly to the forging of airplane engine cylinder heads from aluminum alloys and similar metals, and the present application concerns certain improvements over the methods and apparatus disclosed in my prior applications Serial No. 481,193, filed March 3, 1943, and Serial No. 484,823, filed April 28, 1943.

My prior applications, above referred to, relate to the press forging of cylinder heads in two or three operations, each in a separate die, as distinguished from hammer forging which requires a minimum of fourteen operations.

As set forth in detail in said prior applications, up to the time I developed and put into practice the press forging method and apparatus, cylinder heads for airplane engines were substantially all cast from Duralumin and similar aluminum alloys, but owing to the rapid strides in the development of aircraft engines during the present war the point had practically been reached where the power output of airplane engines could not be further increased because the cast heads were not capable of withstanding the greater pressures which would be developed within the cylinders.

Air craft engineers found that a forged cylinder head would not only have greatly increased tensile strength over the cast head, resulting in a cylinder of much greater strength without any increasein weight or size, but that the greater thermal conductivity of the forged material would considerably increase the cooling efiect of the engine.

Owing however to the shortage of drop hammers and the great number of hammer required to produce a single head it was not possible to commercially produce hammer forged cylinder heads in any substantial quantities. This difiiculty was overcome however by my development of the press forged cylinder head as disclosed in my copending applications above referred to.

The present application contemplates certain improvements upon my press forging method whereby a cylinder head forging is completed with the combustion chamber recess formed therein and the rocker boxes pierced all in a series of continuous steps in a single die, thus greatly increasing the output and reducing the time, labor and expense of producing such cylinder heads. I 1

It is therefore an object of the invention to produce a method employing apparatus includ- 2 ing a single die and cooperating plungers for completely forging and piercing a cylinder head in a single operation.

Another object is the provision of a novel method of producing a completely forged and pierced cylinder head in a single operation comprising a series of successive forging and piercing steps during a single heating of the metal.

A further object is the provision of a method using means whereby upon the closing of the dies the heated blank is forged to nearly complete contour but not entirely filling certain portions of the die, while the successive piercing steps cause the metal to completely fill the die.

A still further object is the provision of a method employing means for preventing the metal from filling the upper portions of the rocker boxes and urging the hot metal to flow toward the reduced end portions of the rocker boxes during the initial step of the operation.

Another object is the provision of a method using removable plates having oppositely tapered projections for insertion into the rocker box cavities of the die during the'initial, or die closing step of the operation.

. The above objects, together with others which will be apparent from the drawings and following description, or which may be later referred to, may be attained by constructing the improved press forging apparatus and operating the same in the manner hereinafter described, and illustrated in the accompanying drawings, in which- Figure 1 is an elevation of press forging apparatus embodying the invention;

Fig. 2, a plan sectional view of the apparatus on a slightly largerscale;

Fig. 3, a detail sectional view of a portion of one of the cylinders, showing the fluid connection for releasing the ram or piston;

Fig. 4, a plan sectional view through the dies and forging, on a larger scale, showing the first step of the operation;

Fig. 5, a detail perspective view'of one of the removable die plates;

Fig. 6, a vertical, sectional view through the dies, showing the forging in the condition shown in Fig. 4, with the piercing plungers withdrawn and the removable die plates removed;

Fig. 7, a plan sectional view similar to Fig. 4, showing the combustion recess forming plunger and the rocker box piercing plungers in operated position and the cylinder head forging in finished condition;

Fig. 8, a fragmentary vertical sectional view through a portion of the dies, showing one rocker The apparatus in which the forging method is carried out includes generally a pair of separable dies arranged to be closed under extreme pressure similar parts by means of a ram, to press forge the cylinder head, a ram operated plunger for forming the combustion recess in the forging, and a pair of similar ram operated plungers for piercing the rockerlboxes of the head.

All of these rams may be operated by any usual and well known power means, either hydraulic, mechanical or electrical, but for the purpose of illustration the rams are disclosed as operated by hydraulic cylinders.

The apparatus may be mounted upon a base plate I5, of considerable thickness, which may be of the general shape indicated in Figure 2 of the drawings. A pillow block it is mounted upon the central portion of the base plate 15, and the lower or fixed die block i1. is mounted upon said pillow block. a

A horizontally disposed hydraulic cylinder i8 is mounted at one end portion of the base plate l5, the squared base portion E9 of said cylinder resting upon the base plate and th depending inverted T-flange 29 being received in the correspondingly shaped transversely disposed groove 2| formed in the upper sideof this end portion of the base plate as best shown in Figs. 1 and2.

This cylinder has a ring 22 mounted in its open end, said ring-being shouldered as at 23 and connected to the end of the cylinder as-by screws or bolts 24. Th ring has an elongated cylindric portion '25 surrounding the reduced portion 26 of the ram or piston 21 and recessed as at 28 to provide a stufiing box within Which'is located packing material'29 held in place by-the gland 30 which is connected to the'outer side of the ring 25by the screws or bolts 3!.

The piston 21 isprovided with the enlarged annular shoulder or flange 32 overhanging the ring 22, as shown in Fig.2, and slidably fitting within the inner wall 33 of the cylinder, being provided with the usual piston rings 34 for sliding engagement with the cylinder wall. Fluid under pressure may be admitted to the outer end of the cylinder by mean of the pipe 35 leading from any suitable source of fluid supply.

For the purpose of reversing the movement of the ram or piston one or more fluid pipes 35 may communicate with the inner end of the'cylinder through the ring 22 as shown in Fig. 3.

The plunger 31, provided with the rounded end 38, for forming the combustion chamber recess in the forging, is attached to the end of the ram or'piston 21 being preferably provided with the flange 39 received in a recess 40 in the end of the piston and attached thereto as by the screws 4!.

A pair of similar, angularly disposed cylinders 42, which may be somewhat smaller than the cylinder R8, are mounted at the other end ofthe base plate, the squared base portion 43 of each of these cylinders resting upon the top of the base plate and the depending inverted T-shaped flanges 44 being received in the correspondingly shaped angularly disposed grooves 45 formed in the upper side of the base plate.

Each of the cylinders 22 has a ring 26 mounted in its open end, the ring being shouldered as at 41 and connected to the end of the cylinder as by the screwsor bolts 28. The elongated cylindric'portion 49 of the ring surrounds the reduced portion 59 of the piston 5| and is recessed to receive packing material 52, the gland 53 being located within the stufling box thus formed and held in place as the screws 5-2 connected to the end of the ring 46.

- The enlarged portion 55 of the ram or piston is slidably mounted within the inner Wall 56 of the cylinder and the usual piston rings 5'! may be provided thereon. Fluid under pressure is admitted to the outer end of each cylinder 42 as by the pipe 53, and for purpose of reversing the movement of these pistons fluid pipes may be connected t the inner end of each cylinder in the manner .indicated at 36 in Fig. 3.

Plungers 59 are. connected to the ends of the rams or pistons 50 as by the flanges 60 and screws 6! and each plunger has the reduced'piercing portion 62 at its end shaped to pierce the rocker boxes of the cylinder head forging as'will be later described.

The vertical cylinder 63 is mounted at the top of the apparatus and provided with the pentagonal base fi l resting upon the squared bases I9 and 23 of the horizontal cylinders l8 and 42 respectively. Near one endthe base 64 is provided with a transversely disposed T-shape groove 65 in its undersurface which receives the correspondingly shaped flange 66 formed upon the upper side of the squared base 19 of thecylinder At its opposite side the base 64 is provided with the angularly disposed IT-shape grooves 61 which receive-the correspondingly shaped flanges 68 formed upon the upper sides of the bases 43 of the cylinders .2. Thus all of the parts of the apparatus are rigidly locked together. If desired vertical flanges 69 may be formed at the meeting edges of the squared bases 43 and the cylinders 32 and connected together as by bolts 'E-El.

The internal construction of the cylinder 63 may be substantially the same as the cylinders i8 and 52 and the ram or piston ll of the cylinder 53 carries the upper or movable die block 12 which cooperates with the lower fixed die block H, the die block being'rigidly connected to the ram as'bythe dovetail flange l3 and correspondingly shaped groove Hi, a removable wedge block 15 being'preferably provided to permit attachment or removal of the die block when necessary.

' Fluid under pressure may be admitted to the upper end of the cylinder 63 as by the pipe 16 and for the purpose of raising the ram or piston H within the cylinder one or more fluid pipes such as indicated at 36 in Fig. 3 may be connectedto the lower end of the cylinder.

4 For the purpose of removing the finished forging from the lower die after the dies are opened a knockout may be provided in'the form of a cylinder l'l formed within the base plate l5 and havinga-piston l8 slidably mounted therein and operated by fluid pressure admitted to the undersideof-the cylinder through the fluidpipe 19. A plunger 801s formed upon-the piston and slidably located through a suitable opening in the pillow block l6 and an opening 8| in the lower die block.

Since the apparatus is designed to form the finished forging, recess and pierce the same all in a single operation of the dies and plungers, enormous power is required and the cylinders or other means which operate the rams may have a capacity as great as 2500 tons.

The fixed and movable die blocks H and 22 respectively have complementary cavities 82 therein of a contour to produce the desired shape of finished forging, said cavities having the angularly disposed reduced extensions 83 on one side to form the rocker boxes. The reduced cylindric passage 84 is formed in the die blocks communicating with one side of the die cavity 82, and enlarged passages 85 are formed in the other end lpOItiOl'l of the die blocks communicating with the rocker box cavities 82.

The plunger 3l, which carries the combustion recess forming portion 33 slidabl-y fits within the cylindric passage 85, and the plungers 59 carrying the reduced rocker box piercing portions 82 have a sliding fit within the passages 85.

In carrying out the improved method to producea cylinder head forging, a blank of aluminum alloy or similar metal, of approximately the exact weight of the forging to be produced, is heated to forging temperature and placed in the cavity of the lower or fixed die 19. This blank may be the usual substantially rectangular block such as is ordinarily used in hammer forging or it may be in the form of a cast ingot or extruded or rolled bar stock somewhat approximating. the general shape of the forging to be produced as indicated generally at 86 in Fig. 11, provided with the reduced angular extensions 8'! for forming the rocker boxes, or of any other shape more or less approximating the contour of the cylinder head to be forged.

The ram H is then operated to lower the upper or movable die 12 into contact with the lower die ll, squeezing the hot metal under extreme continuous pressure in one operation causing the metal to fill the greater portion of the die cavities by leaving a portion of the cavity 82 unfilled as indicated at A in Fig. 6 and leaving a portion of the rocker box cavities unfilled as shown at B in said figure.

Owing to the fact that the rocker box cavities are tapered at each end it is rather difiicult to cause the metal to flow freely towards said tapered ends and in order to assist in overcoming this difficulty, as well as to prevent the hot metal from being extruded through the rocker box cavities 83 into the passages 85, the die plates shown in Figs. 4, 5 and 8 may be used.

Each of these die plates comprises the heaw metal plate 88 having a handle portion 89 by means of which the die plates may be inserted through the slots 99 in the die blocks 11 and 112 and positioned in the passages 85 therein, as shown in Figs. 4 and 8. Each die plate 88 is shaped to conform to the cross-sectional shape of the passages 85.

Upon the inner side of each die plate 88 is formed a projection 9! having a contour corresponding to that of the rocker box cavities 83 and tapered in thickness towards both ends as indicated at 92.

These die plates may be positioned before the dies are closed so that upon the lowering of the upper die the metal in the rocker box extensions of the cavities will be forced against the inner face of the projection 91 as shown in Figs. 4 and 8,

preventing the metal from being extruded through these rocker box cavities into the passages 85 and causing the metal to flow toward the reduced ends of the cavities 83 as shown in Figs. 8 and 6. In Fig. 6 the die plates 88 have been withdrawn to show the shape of the rocker box portions of the forging at this point.

It should be understood that in order to hold the die plates 88 firmly in place when the dies are closed, so as to withstand the pressure of the hot metal against said die plates, the plungers 59 should be operated to hold the reduced portions 62 thereof against the die plates as shown in Figs. 4 and 8. The plungers 59 may then be slightly withdrawn and the die plates removed, as shown in Fig.6. a

While the die blocks remain closed under pressure the plunger 3'! is then operated as shown in Figs. 7 and 10, the rounded extremity 38 thereof forming the combustion recess 93 in this end portion of the forging 94 and causing the metal to entirely fill the die cavities at this end portion of the forging as shown in Fig. 10.

In some cases a skirt as shown at 95 is desired surrounding the combustion recess and this skirt may be extruded in this operation of the plunger 3? as shown in Figs. '7 and 10.

With the die block still held in closed position under pressure, and the plunger 31 held in the extended position as shown in Figs. 7 and 10, the plungers 59 either separately or simultaneously may be operated to the positions shown in Figs. 7 and 9, the reduced extensions 62 thereon piercing the rocker box portions 98 of the forging and forming the cavities or recesses 91 therein and at the same time causing the displaced metal to entirely fill the rocker box cavities as shown in Figs. 9 and 10.

The plungers may then all be withdrawn and the dies opened and the knockout plunger operated to remove the finished forging, as shown in Fig. 12, from the lower die.

The plungers 31 and 59 may be operated in any desired order, or simultaneously, immediately upon the closing of the dies but are preferably operated in the manner above described.

The plungers 3'! and 59 are guided at all times in the passage 84 and respectively, in the die blocks so that these plungers will always move in exactly the same paths, assuring accurate recessing and piercing of each forging.

With this apparatus Operated in this manner it will .be seen that the complete recessed and pierced forging is made with a single heating of the metal and in a single operation of the dies thus greatly reducing the time and labor required for producing these forgings.

By making the blank of approximately the exact weight of the finished forging to be produced, the hot metal when deformed by the dies and plungers will flow into every part Of the die cavity completely filling the same while very little if any flash is formed at any point on the forging.

I claim:

1. The method of making a cylinder head forging with rocker boxes thereon, which consists in heating a metal blank and placing the hot blank between upper and lower dies havin complementary cavities shaped to produce the finished cylinder head forging, closing the dies upon the hot blank squeezing the hot metal under extreme, continuous pressure partially forming the outside contour of the cylinder head and partially forming rocker boxes thereon in. one operation accepts causing-the :hot metal of the blank to fillthe dle cavities with the exception of the top'ofthe upper die cavity and the bottom of the lower :die cavity, then while the die are held :closed under 'pressure, pressing a combustion recess tin-the end portion-of the forging opposite to the rocker boxes causing the blank to expand toward the dies to completely fill the top and bottom of that end portion of the die cavities and :piercing the partially formed rocker boxes of the hot forging cansing the hot metal to completely fill the entire die cavities and completely form the rocker boxes thereon.

2. The method of making a cylinder head forging with rocker boxes therein, which consist :in heating a metal blank and placing the hot blank between upper and lower dies having complementary cavities shaped to produce the finished cylinder head forging, closing the dies upon the hot blank squeezing the hot metal under extreme, continuous pressure partially forming the outside contour of the cylinder head and partially forming rocker boxes thereon in one operation causing the hot metal of the blank to fill theidie cavities with the exception of the top of the upper die cavity and the bottom of the lower-die cavity, then while the dies are held closed under pressure, pressing a combustionrecess in the end portion of the forging opposite to the rocker'boxes causing the blank to expand toward the dies to completely fill the top and bottom-of that end portion of the die cavities andthen piercing the partially formed rocker boxes of the hot forging causing theihot metal to completely fill the entire-die cavities and completely form the rocker boxes thereon.

3 The method of making a cylinder head for ing with rocker boxes thereon, which consists in heating a metal blank and placing the hot blank between upper and lower dies having complementary cavities shaped to produce the finished cylinder head forging, closing the dies upon the hot blank squeezing the hot metal under extreme, continuous pressure partially forming the outside contour of the cylinder head and partially forming rocker boxes thereon in 'one operation causing the hot metal of the blank to fillthe die cavities with the exception of the top of the upper-die cavity and the bottom of the lower die cavity, then while the dies are held closed under pressure, pressing a combustion recess in the end portion of the forging opposite to the rocker boxes causing the blank to expand toward the dies to completely'fill the top and'bottom of that endportion of the die cavities and simultaneously piercing the partially formed rocker boxes of the hot forging causing the hot metal to completely fill the entire die cavities and completely form the rocker boxes thereon.

4. The methodof'making a cylinder head forging with rocker boxes thereon, which consist [in heating a metal blank and placing the hot blank between upper and lower dies :having complementary cavities shaped to produce the finished cylinder head forging, closing the dies upon the hot blank squeezing the hot metal underextreme, continuous pressure partially forming the outside contour of the cylinder head and partially forming rocker boxes thereon in one operation causing the hot metal of the blank to fill thedie cavities with theexceptionof the top of the upperdie cavity andthe bottom of the lower die cavityythen while the dies are held closed under pressure, pressinga combustion recess-inthe end-portionof the forging opposite to'the rocker boxes causing the blank toexpand-towardthe dies tocompletely fillthe toprand bottom of that end portion of the die ;cavities -.and Isimultaneously extruding a skirt .-:of :lessfdiaineter than the head around the combustion recess and piercing the partially formedrockerboxes of the :hot f r ng c n thehotmetal .tolcompletely fill the entire die cavities and completely form the rocker boxes thereon.

' 5. The method of making'a cylinder head forg- (ing with rocker boxes thereon, which consists in :heating ametal blank and placing the hot blank between upper and lower dies havingcomplemen- :tary cavities shaped to produce the finished cylinder head forging, closing the dies upon the hot ;blan'k squeezing the hot metal under extreme, continuous pressure partially forming the outside icontour .of the cylinder head and partially formingrocker boxes thereonin one operation causing the hot metal of the blank to fill the die cavitieswith theexception of "the top of the'upper die cavity and the bottom of the lower die cavity, thenwhile :the dies are held closed under pres- ;sure, pressing a combustion recesslin the end portion of the forging opposite to the rocker boxes causing the blank to expand toward the dies to completelyifill the top and bottom of that end portion of the .die cavities and extruding a skirt of less diameter than the head around the comzbustion recess and then piercing the partially iormedriocker boxes of .the hot forging causing the zh'otrmetal to completely =fi1l the entire die :cavitiesiand completely form the rocker boxes thereon.

16. "The method of makingia, cylinder head forging with trocker boxes thereon, which consists n heatingametaliblank and placing the hot blank between :upper and lower dies having complementary cavities shaped to produce the finished .cylinder'head forging, closing the dies upon the hot blank squeezing the hot metal under extreme, continuous :pressure'partially forming the outside contour :of'the cylinder head and partially formingzrockerboxes'thereon in one operation causing the hot :metal of the blank to fill the die cavities with the exception of the top of the upper die cavity and the bottom of the lower die cavity, then while the dies are held closed under pressure, rpressin'gsa' combustion recess in the end portion of the forging opposite to the rocker boxes causing the blank to expand toward the dies to completely ifill the top and bottom of that end 'port'i'onlof ithedie cavities and simultaneously exltruding :a skirt of less diameter than the head around the-combustion recess and simultaneously piercing the .partiallyformed rocker boxes of the ;hot iforging causing the hot metal to completely fill the entire die cavities and completely form 'therocker boxesthereon.

7. The method of making a cylinder head forging with rocker boxes thereon, which consists in heatin'g a metal' blank and placing the hot blank rb'etweeniupper and lower dies having complementary-cavit-ies shaped to produce the finished cylinder hea'd forging, closing the dies upon the hot blank squeezing the hot metal under extreme, :continuoiis pressure partially forming the outside contour of the cylinder head and partially form- ;ing rocker .boxes thereon, and preventing the metal-from filling the outer nds of the rocker boxes in one operation causingthe hot .metal of the blank to fill the die cavities with the excep- :tion'of the top 'ofthe upper die cavity and the bottom of :the slower die cavity, then while the dies .are"held closed :under pressure, pressing .a combustion-recess in the end'portion of the forging opposite to the rocker boxes causing the blank to expand toward the dies to completely fill the top and bottom of that end portion of the die cavities and piercing the partially formed rocker boxe of the hot forging causing the hot metal to completely fill the entire die cavitie including the outer ends of the rocker boxes and completely form the rocker boxes thereon.

8. The method of making a cylinder head forging with rocker boxes thereon, which consists in heating a metal blank and placing the hot blank between upper and lower dies having complementary cavities shaped to produce the finished cylinder head forging, closing thedies upon the hot blank squeezing the hot metal under eX- treme, continuous pressure partially forming the outside contour of the cylinder head and partially forming rocker boxes thereon, and preventing the metal from filling the outer ends of the rocker boxes in one operation causing the hot metal of the blank to fill the die cavities with the exception of the top of the upper die cavity and the bottom of the lower die cavity, then while the dies are held closed under pressure, pressing a combustion recess in the end portion of the forging opposite to the rocker boxes causing the blank to expand toward the dies to completely fill the top and bottom of that end portion of the die cavities and then piercing the partially formed rocker boxes of the hot forging causing the hot metal to completely fill the entire die cavities including the outer ends of the rocker boxes and completely form the rocker boxes thereon.

9. The method of making a cylinder head forging with rocker boxes thereon, which consists in forming a substantially rectangular metal blan having angular ribs at two adjacent corners thereof, heating the blank and placing the hot blank between upper and lower dies having complementary cavities shaped to produce the finished cylinder head forging, closing the dies upon the hot blank squeezing the hot metal under extreme, continuous pressure partially forming the outside contour of the cylinder head and partially forming said angular ribs into rocker boxes in one operation causing the hot metal of the blank to fill the die cavities with the exception of the top of the upper die cavity and the bottom of the lower die cavity, then While the dies are held closed under pressure, pressing a combustion recess in the end portion of the forging opposite to the partially formed rocker boxes causing the blank to expand toward the dies to completely fill the top and bottom of that end portion of the die cavities and piercing the partially formed rocker boxes of the hot forging causing the hot metal to completely fill the entire die cavities and completely form the rocker boxes thereon.

10. The method of making a cylinder head forging with rocker boxes thereon, which consists in forming a substantially rectangular metal blank having angular ribs at two adjacent corners thereof, heating the blank and placing the hot blank between upper and. lower dies having complementary cavities shaped to produce the finished cylinder head forging, closing the dies upon the hot blank squeezing the hot metal under extreme, continuous pressure partially forming the outside contour of the cylinder head and partially forming said angular ribs into rocker boxes in one operation causing the hot metal of the blank to fill the die cavities with the exception of the top of the upper the cavity and the bottom of the lower die cavity, then while the dies are held closed under pressure, pressing a combustion recess in the end portion of the forging opposite to the partially formed rocker boxes causing the blank to expand toward the dies to completely fill thetop and bottom of that end portion of the die cavities and then piercing the partially formed rocker boxes of the hot forging causing the hot metal to completely fill the entire die cavities and completely form the rocker boxes thereon.

11. The method of making a cylinder head forge ing with rocker boxes thereon, which consists in forming a substantially rectanglar metal blank having angular ribs at two adjacent corners thereof, heating the blank and placing the hot blank between upper and lower dies having complementary cavities shaped to produce the finished cylinder head forging, closing the dies upon the hot blank squeezing the hot metal under extreme, continuous pressure partially forming the outside contour of the cylinder head and partially forming said angular ribs into rocker boxes in one operation causing the hot metal of the blank to fill the die cavities with the exception of the top of the upper die cavity and the bottom of the lower die cavity, then while the dies are held closed under pressure, pressing a combustion recess in the end portion of the forging opposite to the partially formed rocker boxes causing the blank to expand toward the dies to completely fill the top and bottom of that end portion of the die cavities and simultaneously extruding a skirt of less diameter than the head around the combustion recess and piercing the partially formed rocker boxes of the hot forging causing the hot metal to completely fill the entire die cavities and completely form the rocker boxes thereon.

12. The method of making a cylinder head forging with rocker boxes thereon, which consists in forming a substantiall rectangular metal blank having angular ribs at two adjacent corners thereof, heating the blank and placing the hot blank between upper and lower dies having complementary cavities shaped to produce the finished cylinder head forging, closing the dies upon the hot blank squeezing the hot metal under extreme, continuous pressure partially forming the outside contour of the cylinder head and partially forming said angular ribs into rocker boxes and preventing the metal from filling the outer ends of the rocker boxes in one operation causing the hot metal of the blank to fill the die cavities with the exception of the top of the upper die cavityand the bottom of the lower die cavity, then while the dies are held closed under pressure, pressing a combustion recess in the end portion of the forging opposite to the partially formed rocker boxes causing the blank to expand toward the dies to completely fill the top and bottom of that end portion of the die cavities and piercing the partially formed rocker boxes of the hot forging causing the hot metal to completely fill the entire die cavities including the outer ends of the rocker boxes and completely form the rocker boxes thereon.

13. The method of making a cylinder head forging with rocker boxes thereon, which consists in forming a substantially rectangular metal blank having angular ribs at two adjacent corners thereof, heating the blank and placing the hot blank between upper and lower dies having complementary cavities shaped to produce the finished cylinder head forging, closing the dies upon mew-6 7. 5

T1 the hot-blank squeezing"- the hotfmetal under ex-:- ti'eme; centinuous pressunei partially forming the outs/me"-. ccmtour of the cylinder; head; and par"- tia lly' forming said angular ribsdntorockeriboxes and: preventing :the: meta1'='fronr filling the cuter ends: of' the r'ockerbcxesin .oneoperation causing the-hot metali of the blank: to fillthe' die cavities with: the. exception of. theitopt of the". upper? die cavity and; the bottom of the lowerrdiezcavity; then while the. dies. are held closedlunder'presrsure; pne'ssing: a; combustion; recessrint. the end, portion; of the forging: opposite to" the". partially formedc'mcken boxes causing: the blank-.to; expand towam thesdiese to: completely: fill the; top: and bettoxmofi that? emi porticrr of. the: dies'cavit-ies: and simultaneously, extruding-1a; skirt of: less diameter than". the head: around.- they combustiongrecess; and Qi'ercinggthe partially formed; nockerrbcxes. ofiithe hot; ferging; causing the: hot: mGtHJYt/O completely fi11=the entiredie cavitieszincluding: the outer," ends cfthe rocker boxes and: completely form-the rock erhoxes-thereon:

CHARLES A.. RAUCHLER'.

REFERENCES CITED The following references are of record in the file of this; patent:

UNITED STATES PATENTS Numben Nalme Date 23302415. Gazey .Nov. 17, 19.42 1,929.;802- Brauchler Oct. 10, 1933 1;;328; 276 Fuchs Jan. 20, 1:924) 2; 24&, 954; Lenz June in, 1941 2024 285- Handler Dec. 17,1935

FOREIGN PATENTS Number Country Date-v 265,39'0r Great: Britain Feb; 10; 1927 

